CVE-2026-66729

facil.io 0.6.0 through 0.7.6 contains an integer underflow vulnerability in the multipart MIME body parser that allows unauthenticated remote attackers to crash the server process by sending a crafted Content-Disposition header with an empty field name. Attackers can trigger a uint32_t wraparound in http_mime_parser.h causing an out-of-bounds memory read past the name pointer, resulting in a bus fault that crashes the handling worker with a single POST request.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/theopaid/Out-of-Bounds-Read-in-facil.io-MIME-Parser-leads-to-Server-Crash
https://tpaidakis.com/writeups/facilio-parser-dos/
https://www.vulncheck.com/advisories/facil-io-integer-underflow-dos-via-multipart-mime-body-parser

Configurations

No configuration.

History

24 Oct 2026, 13:10

Type	Values Removed	Values Added
Summary		(es) facil.io 0.6.0 hasta 0.7.6 contiene una vulnerabilidad de desbordamiento negativo de enteros en el analizador de cuerpos MIME multipartes que permite a atacantes remotos no autenticados bloquear el proceso del servidor enviando una cabecera Content-Disposition manipulada con un nombre de campo vacío. Los atacantes pueden desencadenar un desbordamiento circular de uint32_t en http_mime_parser.h, causando una lectura de memoria fuera de límites más allá del puntero ’name’, lo que resulta en un fallo de bus que bloquea al trabajador de manejo con una única solicitud POST.

Information

Published : 2026-07-27 17:16

Updated : 2026-10-24 13:10

NVD link : CVE-2026-66729

Mitre link : CVE-2026-66729

CVE.ORG link : CVE-2026-66729

JSON object : View

Products Affected

No product.

CWE

CWE-125

Out-of-bounds Read

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